Hi and Welcome to Wikipedia. :) When it comes to External links, we abide by the Wikipedia External links guideline. The link you added, Groover User Group is a forum of sorts. But, the WP:EL guidelines states Links to social networking sites (such as MySpace), discussion forums or USENET should be avoided. Under that clause, the link to the site cannot be accepted. As for the rest of the sites, if they are really important and notable enough, they will get their own articles, and we can then link to those articles in a See also section in the Groove article. But as they stand, the links do not add value to the Groove article. And as such I removed them. In addition to WP:EL, inclusion of external links is also subject to the WP:SPAM guidelines. Take a look at that also.
However, I am sorry I had to revert your first edit. Don't get disheartened, you are not alone (even my first edit, actually a couple of edits, were reverted). I would also like to inform you that the Microsoft Office Groove article is not at the quality level we would like to see - it needs to be vastly improved. Since you said you are quite experienced in collaborative software (and from the forums, I assume, well versed with the technicalities of Groove), you can add to the text of the article itself. It certainly deserves to be a detailed reference of what Groove is what it can do. And given your expertise, I do think you can be a significant contributor to that end.
Wish you all the best with your future editing endeavours. --soum (0_o) 15:07, 27 March 2007 (UTC)